The invention relates to a method to monitor an area and a device for carrying out the method.
In publicly accessible, highly frequented buildings such as in supermarkets, theaters and sports halls, for example, it is necessary to provide emergency exits. In this case, it is of importance, in particular, that emergency exits are sufficiently available. It is necessary to ensure that these emergency exits are not blocked with any objects, in order that their effectiveness is not impaired. However, at present no suitable technical means are known for effectively and reliably identifying an obstruction of emergency exits.
This is because e.g. light barriers are used for monitoring purposes. In the case of these light barriers, however, it has emerged that they are too complicated to monitor entire areas. A further possibility is afforded by the use of weight sensors installed in the ground. However, these can only be installed with high structural outlay.
A further known approach consists in monitoring affected areas by means of a video camera. Currently known methods for monitoring by means of a video camera are based on the principle of identifying image brightness changes. However, these methods are very sensitive to changes in the illumination conditions and are therefore not sufficiently robust.
Methods to monitor areas and in particular to monitor persons in said areas are known.
The document DE 102 10 926 A1 describes a device and a method for tracking at least one object in a scene. In the method, if a moving object stops moving and comes to a standstill, the duration of staying at a standstill is counted. Depending on the aforesaid duration, a signaling is generated. In this case, the object is described by a list or a matrix with regard to the direction of movement and the time. In this way, an atypical behavior pattern is identified in the monitored scene in which moving objects are usually situated.